1. Field of the Invention
The present invention relates to a disk-loading apparatus for loading a CD and a DVD to their reproducing positions, and more particularly to a rotation-transmitting mechanism that transmits the rotation of a loading motor.
2. Description of the Related Art
FIG. 16 is a top view of a conventional disk-loading apparatus 100.
Referring to FIG. 16, a main chassis 2 supports a tray 3 thereon such that guides 2a–2f guide the tray 3 to slide on the main chassis 2. The tray 3 carries a disk, not shown, placed thereon and moves into the apparatus for loading the disk and out of the apparatus for discharging the disk. The tray 3 is formed with a rack 3a in an underside thereof on one side of the tray 3.
A drive gear 120 is rotatably mounted on the main chassis 2 and has a small gear 120a in mesh with the rack 3a. Likewise, a drive gear 121 is rotatably mounted on the main chassis 2 and has a small gear 121a in mesh with a large gear 120b of the drive gear 120.
FIG. 17 is a perspective view of a pertinent portion of a rotation-transmitting mechanism of a loading motor of FIG. 16.
Referring to FIG. 17, the small gear 121a has a disk 121b mounted to an underside thereof, the disk 121b having a conical surface 121c. A loading motor 122 has a friction wheel 123 attached to a shaft thereof, the friction wheel 123 being in the shape of a truncated cone. The shaft of the loading motor 122 extends parallel to the main chassis 2 so that the conical surface 121c of the friction wheel 123 is in pressure contact with the conical surface 121 of the disk 121b. Thus, the rotation of the loading motor 122 is transmitted to the gear 121 through friction engagement of the friction wheel 123 with the disk 121.
The loading motor 122 is mounted on an L-shaped mounting member 124 by means of a screw 101. The L-shaped mounting member 124 is firmly mounted on the main chassis 2 by means of screws 102. The chassis 2 is mounted on a player chassis, not shown, by means of rubber dampers 80, 81, and 82 (FIG. 16).
A description will now be given of the operation of the above-described mechanism in which the tray 3 is moved in an insertion direction and a discharging direction relative to the main chassis 2.
When the loading motor 122 rotates, the friction wheel 123 drives the disk 121b of the gear 121 to rotate through friction engagement. Simultaneously, the rotation of the gear 121 is transmitted to the gear 120. The gear 120 in turn drives the tray 3 through rack-and-pinion engagement to move in either a direction shown by arrow A or a direction shown by arrow B of FIG. 16, depending on the direction of rotation of the loading motor 122.
The conventional disk-loading apparatus uses a friction wheel 123 formed of a highly frictional material such as rubber. The rotation of the loading motor 122 is transmitted to a driven mechanism through a frictional force. Therefore, the repetitive driving operation over a long time causes the friction wheel 123 to wear and dust to accumulate, so that the frictional force decreases gradually to cause the friction wheel 123 to slip on the conical surface 121c of the disk 121. As a result, the tray 3 cannot be inserted into and discharged out of the apparatus properly.